The human genome contains the instructions to build and maintain all cells in our body. We inherit this “cell manual” from our parents and pass it on to our children. Errors in this manual can change cell properties and trigger diseases, including cancer. More than half of our genome is made up of ‘junk’ DNA, a large part of which is comprised of potentially mobile pieces called transposons, or 'jumping genes', which are believed to have evolved from ancient viruses.
Transposons can be viewed as 'loose pages' within our cell manual because they can change their position, and their distribution differs within each person’s genome. Transposons inserted in genes can disrupt their function and impair important cell processes. However, more recently it has been proposed that transposons might also play more beneficial roles in our body, such as in the communication between different cells in our brains.
Researchers in the Centre for Neural Circuits and Behaviour in Oxford have now used state-of-the-art single-cell sequencing on the brains of fruit flies, a well-established model organism in neuroscience, to investigate transposon activity in the brain at an unprecedented level of detail. This new analysis revealed that transposons were not uniformly active throughout the entire brain of flies, but rather showed highly distinct patterns of expression. Moreover, these patterns were tightly linked to genes located near transposons. This indicates that transposons might play an important altruistic role in our body.